Impact on Premiums from Health Care Market Concentration: Evidence from the Affordable Care Act's Health Insurance Mark

For each state, the research team will estimate the effects of health insurance and provider market concentration on plan premiums in the ACA marketplaces over the period 2014 to 2018. The team also will investigate whether findings vary according to marketplace model (e.g., state-run vs. federally operated) and state insurance market regulations. This grant, which will support the first year of work, will enable the researchers to secure the relevant data sets and produce a report on state trends in market concentration and premiums in 2014 and later. A multivariate analysis of all 51 marketplaces would be performed in year 2, subject to Board approval. Key data sources will include: 1) Commonwealth Fund grantee Jon Gabel’s health insurance premium database; 2) HealthLeaders-Interstudy’s Managed Market Surveyor (insurer concentration); 3) the American Hospital Association’s Annual Hospital Survey (hospital concentration); and 4) IMS Health’s Healthcare Relational Services (HCRS) data (physician organization concentration). Findings will inform policymakers about the degree of competition in health care markets and whether relative levels of market consolidation in insurer and provider markets make a difference in premium trends. In addition, this research will inform antitrust enforcement actions, guide decisions on whether future mergers and acquisitions should be approved, and provide insights to state and federal officials running health insurance marketplaces.